Samson 3768, Mounting And Operating Instructions

Page: 12 / 48

12 EB 8356 EN
Attachment to the valve
Actuator with 120 cm² diaphragm area
The signal pressure is transmitted to the dia-
phragm chamber over the switchover plate.
1.
Remove the M3 screw plug at the back
of the limit switch and use the blanking
plug from the accessories to seal the sig-
nal pressure output (Output 38) at the
side.
2. Mount the limit switch so that the hole in
the intermediate plate (15) covers the
seal in the hole of the yoke.
3. Align the switchover plate with the corre-
sponding actuator symbol. Fasten it to
the yoke.
3.2 Attachment according to
IEC 60534-6
The mounting parts listed in Table 5 are re -
quired for limit switch attachment. The rated
travel of the valve determines which lever is
to be used.
An adapter housing is used for NAMUR at -
tachment. The valve travel is transmitted by
the lever (18) and the shaft (25) to the brack -
et (28) of the adapter housing and then
passed on to the pin (27a) on the lever of
the limit switch.
To ensure that the pin (27a) is properly locat-
ed in the bracket (28), fix the spring includ -
ed in the accessories at the back of the posi-
tioner housing as illustrated in Fig. 3.
The limit switch can be mounted either on the
left or right side of the valve.
Spring Screw plug
Fig. 3: Installing the spring on the back
3.2.1 Mounting sequence
Î
Select the required mounting parts from
the tables on page 20 onwards.
Valve with cast yoke:
1. Screw the plate (20) to the stem connec-
tor of the actuator and plug stems using
the countersunk screws.
Use the additional bracket (32) for 2100
and 2800 cm² actuators.
2. Remove the rubber stopper from the
adapter housing and fasten the adapter
housing either on the left or right of the
NAMUR rib using the hexagon head
screw.
Valve with rod-type yoke:
1. Screw the plate (20) to the follower
clamp of the plug stem.
2. Screw the studs (29) into the adapter
housing.
3. Place the adapter housing with the plate
(30) onto either the left or right valve rod
and screw tight using the nuts (31). Make
sure that the adapter housing is at the
18 Lever N1, N2
19 Pin
20 Plate
21 Clip
22 Clamping plate
23 Screw
24 Pointer
25 Shaft
26 Lever of positioner
27a Coupling pin
27b
Lock nut
28 Bracket
29 Studs
30 Plate
31 Nuts
32 Mounting bracket
2
1,5
1
28 26
A B
24 25 22
32
31
20 19
19 21 20 23 18
27b
27a
29
30
Mounting position
Attachment to
NAMUR rib
Attachment to rods
Fig. 4: Attachment according to NAMUR (shown for left attachment)